It would be (x)(x+7)=170
If you want it solved, then you would get:

=0
(x+17)(x-10)=0
And since you can't have a negative length (-17), x=10
So your side lengths would be 10 and 17 (10+7), which would give you an area of 170.
Hope that helps.
Answer:
10% out of 100%.
Or 4/40=1/10 which is 10%.
Shen has ridden her bike for 10% of the course
Answer:
Divide by 80 on both sides
Answer:
....................21 .....................